Two-stage starting system for internal combustion engines



1960 c. A. MENDENHALL 2,925,810

TWO-STAGE STARTING SYSTEM FOR INTERNAL COMBUSTION ENGINES Filed Aug. 4,1958 2 Sheets-Sheet 1 a INVENTOR.

ATTORNEY 7 Feb. 23, 1960 c'. A. MENDENHALL 2,925,810

TWO-STAGE STARTING SYSTEM FOR INTERNAL COMBUSTION ENGINES Filed Aug. 4,1958 2 Sheets-Sheet 2 United States Patent TWO-STAGE STARTING SYSTEM FORINTERNAL COMBUSTION ENGINES Charles A. Mendenhall, Horseheads, N.Y.,'assignor to Bendix Aviation Corporation, Elmira Heights, N.Y., acorporation of Delaware Application August 4, 1958, Serial No. 752,853

6 Claims. (Cl. 123-179) The present invention relates to a two-stagestarting system for internal combustion engines, and more particularlysuch a system including means for optionally energizing the startingsystem by reduced voltage applied to the starter motor.

It is an object of the present invention to provide a novel two-stagestarting system incorporating a unitary manual switching device foroptionally energizing the starting motor at either of two operatingpower levels.

It is another object to incorporate in such a device a manually operateddetent means for insuring traversal of the drive pinion into mesh withthe engine gear upon initial rotation of the starting motor.

It is another object to provide such a device in which the switchingmeans and the detent means are operated by a unitary controlling device.

It is another object to provide such a device which is so arranged thatthe detent is rendered operative only while the starting motor isenergized at its lower power level.

It is another object to provide such a device in which the meshingdetent is rendered inoperative as soon as its function is accomplished.

Further objects and advantages will be apparent from the followingdescription taken in connection with the accompanying drawings in which:

Fig. 1 is a semi-diagrammatic view of a starting system constituting apreferred embodiment of the invention, the switch means being shown inelevation, and the starter gearing being also shown in side elevation,partly broken away and in section;

Fig. 2 is a sectional detail of the starter gearing taken substantiallyon the line 22 of Figure 1;

Fig. 3 is an elevation of the switch means with the cover removed,partly broken away and in section;

Fig. 4 is a section of the switch means taken substantially on the line44 of Fig. l; and

Fig. 5 is a section of the switch means taken substantially on the line5-5 of Fig. 1.

In Fig. 1 of the drawings, there is illustrated a battery 1 which isgrounded at 2- and connected by a lead 3 to a terminal 4 of a switchingdevice indicated generally by the numeral 5. A second terminal 6 of theswitching device is connected by a lead 7 to a starting motor 8 which isgrounded at 9 to complete the starting circuit.

The armature shaft 11 of the starting motor 8 has rigidly mountedthereon a driving head 12 which is connected through a drive spring 13and an overrunning clutch 14 to a screw shaft 15. A control nut 16 isthreaded on the screw shaft 15 and rigidly connected by a barrel mem ber17 to a pinion 18 which is movable thereby into and out of mesh with agear 19 of the engine to be started, the meshing position of the pinionbeing defined by a stop ring 21.

The switching device 5 has a third terminal 22 which is connected by aresistor 23 to the battery terminal 4 of the switching device. As bestshown in Fig. 3, the switching device incorporates manually operablemeans 2,925,810 Patented Feb. 23, 1960 for optionally connecting themotor terminal 6 thereof to either one of the terminals 4 or 22. Forthis purpose a pair of plungers 24 and 25 are slidably mounted inparallel relation in the casing 26 of the switching device. A contact 27is fixedly mounted on the cover or terminal plate 28 of the casing whichcarries the terminals 4, 6 and 22, insulated therefrom as indicated at29 in Fig. 5, and connected to the terminal '22. A second contact 31 issimilarly mounted and connected to the terminal 4, and a third contact32 is similarly mounted on the plate 28 and connected to the terminal 6,said three contacts being coplanar and being spaced on opposite sides ofthe plungers 24 and 25 as best shown in Fig.4.

A movable contact 33 is slidably mounted on the plunger 24 and normallypressed against a stop ring 34 by means of a spring 35, this contactbeing in the form of a disc adapted to connect fixed contacts 27, 32when the plunger 24 is drawn to the left in Fig. 3 for that purpose. Amovable contact 31 is similarly mounted on the plunger 25, backed up bya spring 36, and arranged to connect contacts 32 and 31 when the plunger25 is moved to the left.

The plunger 24 has fixedly mounted thereon a manually operable knob 38whereby the plunger may be moved in either direction from its normalposition as illustrated in Fig. 3. The plunger 24 has a pin 39projecting therefrom and plunger 25 has a similar pin 41 located in acorresponding position. A lever 42 is pivoted to the casing 36 as bymeans of a stub shaft 43 and is provided with slots 44 and 45 throughwhich the pins 39 and 41, respectively, project. Springs 46 and 47anchored to the wall of the casing 26 are attached to the ends of thelever 42 and yieldingly maintain the lever, and consequently theplungers 24 and 25, in their normal position as illustrated.

In order to insure traversal of the pinion 18 into mesh with the enginegear 19 by the screw-jack action of the screw shaft 15 and control nut16, the control nut is formed with a plurality of lugs 48 projectingoutside of the barrel member 17 as shown in Figs. 1 and 2, and a detentmember 49 is slidably mounted in the motor casing 51 for movement intoand out of the path described by the lugs 48 when the pinon 18 is in itsidle position. Means for actuating the detent 49 to cause it to engagethe lugs 48 is provided comprising a bell crank lever 52, pivoted at 53on the motor casing, having one arm 54 engaging the head 55 of thedetent and its other arm 56 connected by a flexible cable or Bowden wire57 to the switch plunger 24. A spring '58 normally maintains the detent49 in retracted position, and movement of the plunger 24 to the left inFig. 3 to close the switch contacts 27, 33, 32, actuates the lever 52 bymeans of the flexible cable to move the detent into operative position.

In operation, when it is desired to start the engine, the operator willpull on the knob 38 thereby moving the detent 49 into operative positionand then closing the switch contacts 27, 33 and 32 whereby the startingmotor 8 is connected to the battery 1 through the resistor 23. Thestarting motor is thus energized at its lower power level, and theconsequent rotation of the screw shaft 15 moves the pinion 18 into meshwith the engine gear 19, since rotation of the pinion is prevented bythe detent 49. As soon as the pinion enters into mesh with the enginegear, the lugs 48 move out of contact with the detent 49 which, itsfunction being accomplished, then becomes inoperative to resist rotationof the control nut.

After the pinion has been fully meshed, the operator then pushes on theknob 38 whereby the switch contacts 27, 33, 32 are opened and contacts32, 37 and 31 are closed, thus connecting the starting motor directly tothe battery and consequently energizing it with the full battery voltagefor the cranking operation.

When the engine starts, the pinion 18 is returned to its idle positionby the overrunning of the engine gear 19, and, upon release of the knob38 by the operator, the switch contacts 33, 37 are returned to theirnormal positions by the springs 46, 47.

Although one form of the invention has been shown and described indetail, it will be understood that changes may be made in the design andarrangement of the parts without departing from the spirit of theinvention.

I claim: I

1. In a two-stage starting system for internal combustion engines, astarting motor, gearing including a motordriven pinion and means fortraversing the pinion into mesh with a gear of the engine to be startedresponsive to acceleration of the motor; an electrical circuit forenergizing the motor including a battery, a resistor and a switch inseries therewith, a second switch arranged, when closed, to short-circutthe resistor, a manually operable switch-actuating member, and meanswhereby movement of said member in one direction closes one of saidswitches and movement of the same in the opposite direction closes theother of said switches.

2. A starting system as set forth in claim 1 including further a detentmoveable into and out of position to resist rotation of the pinion priorto its engagement with the engine gear, and means operated by saidmanual switchactuating member to move said detent into and out ofoperative position.

3. A starting system as set forth in claim 2 in which the means formoving the detent is actuated by said manual member to move the detentinto operative position responsive to movement of the manual member toclose said first mentioned switch.

4. A starting system as set forth in claim 2 in which the detent isarranged to become inoperative when the pinion enters into mesh with theengine gear.

5. A starting system as set forth in claim 1 in which said switches eachcomprise a plunger and a movable contact mounted thereon, said manualmember being mounted on one of said plungers, and means including alever so connecting said plungers that movement of said one plunger in aswitch-opening direction causes movement of the other plunger in aswitch-closing direction.

6. A starting system .as set forth in claim 5 including further meansconnecting said one plunger to the detent to move the detent intooperative position responsive to movement of said one plunger to closeits switch contacts.

References Cited in the file of this patent UNITED STATES PATENTS1,733,911 Seifert Oct. 29, 1929 2,808,964 Forstrom May 18, 19372,556,063 Buxton June 5, 1951 2,727,158 Seilly Dec. 13, 1955 2,769,099Peterlik et a1. Oct. 30, 1956 2,855,063 Schwarzenback et a1 Oct. 7, 19582,882,421 Mendenhall Apr. 14, 1959

